Envirohub Marlborough zero waste coordinator Heather Barnes said they wanted to get an idea of people's use of reusable cups before launching their campaign.
The campaign is part of the nationwide Plastic Free July movement.
Malburians were asked to participate in 'BYO Cup Mondays,' but were also encouraged to use their reusable cups as much as possible.
Barnes said they chose Monday, but people should really bring their reusable cup every day. However, Envirohub thought people might struggle with remembering to bring their cup every day, so starting with the beginning of the week was a good time to introduce the habit.
People can post pictures of themselves with their cups on the Envirohub Marlborough Facebook page or tag them on Instagram for the chance to win a reusable gift pack.
More than 25 cafes in the region have their 'Reusable Cups Welcome Here' stickers up as well.
70 percent of survey respondents stated they were more likely to go to a cafe that is making an effort to reduce single-use cups.
After this response, Envirohub Marlborough conducted another survey, but for cafe owners.
Barnes said she went to about 25 cafes to introduce the campaign, and the response was great.
If any cafe owners have not received a sticker and would like one, they can email email@example.com.